Vaccination with a BCG Strain Overexpressing Ag85B Protects Cattle against Mycobacterium bovis Challenge

RIZZI C; BIANCO MV; BLANCO FC; SORIA MA; GRAVISACO MJ; MONTENEGRO V; VAGNONI L; BUDDLE B; GARBACCIO S

PLOS ONE

PUBLIC LIBRARY SCIENCE

Lugar: San Francisco; Año: 2012 vol. 7 p. 1 - 10

1932-6203

Mycobacterium bovis is the causative agent of tuberculosis in cattle but also infects other animals, including humans.Previous studies in cattle have demonstrated that the protection induced by BCG is not complete. In order to improve theprotection efficacy of BCG, in this study we overexpressed Ag85B in a BCG Pasteur strain, by using an expression systembased on the use of an auxotrophic strain for the leucine amino acid, and complementation with leuD. We found thatvaccination of cattle with BCG overexpressing Ag85B induced higher production of IL-17 and IL-4 mRNA upon purifiedprotein derivative (PPDB) stimulation of peripheral blood mononuclear cells (PBMCs) than vaccination with BCG. Moreover,the IL-17 mRNA expression after vaccination negatively correlated with disease severity resulting from a subsequentchallenge with M. bovis, suggesting that this cytokine is a potential biomarker of cattle protection against bovinetuberculosis. Importantly, vaccination with the recombinant BCG vaccine protected cattle better than the wild-type BCGPasteur.